Technical Field
The present disclosure relates to a vehicle occupant protection device.
Related Art
An airbag device is known (see Japanese Patent Application Laid-Open (JP-A) No. 2000-344044) that, in the event of a collision, supplies gas from an inflator through a gas supply pipe that is fixed to a seat back to a bag that is attached to the gas supply pipe, and causes this bag to inflate so as to cover a front and sides of a head portion of a vehicle occupant. In addition, an airbag device is known (see JP-A No. 2013-018378) in which an airbag for a head portion is deployed towards the front at left and right end portions of a seat headrest, and join together at the front surface of the vehicle occupant head portion, while an auxiliary airbag for a head portion is deployed towards the front from a central portion of the seat headrest so as to join with the pair of head portion airbags. In addition to these, a structure in which an airbag that inflates so as to cover the front and sides of the head portion of a vehicle occupant is housed in a seat back is disclosed in German Patent Application Publication No. 19859988A1.
In the structure disclosed in JP-A No. 2000-344044, because the gas supply pipe is provided such that it protrudes above the seat back, it has an unattractive appearance and the gas supply pipe is an obstruction when the vehicle seat is being operated.
On the other hand, in the structure disclosed in JP-A No. 2013-018378, it is difficult to guarantee a satisfactory mutual join strength between the pair of head portion airbags that are joined together after being inflated and deployed, or a satisfactory join strength in when the auxiliary head portion airbag is joined to the pair of head portion airbags.
As a measure to counter such drawbacks, consideration may be given to employing a structure in which an airbag that is formed as an integrated bag body is housed in an upper portion of a vehicle seat, and this airbag is inflated and deployed so as to cover the head portion of a vehicle occupant from the front and from both the left and right sides. However, there is a possibility that, upon being supplied with gas, the airbag will become caught on the head portion of the vehicle occupant or on the vehicle cabin ceiling or the like as it passes over the headrest and the vehicle occupant, and there is room for improvement from the standpoint of improving the deployment performance of the airbag.